The present invention relates to a method of producing a vane damper which comprises a body with a space for at least one rotatable vane which divides the space into two part spaces located on either side of the vane. Because of the rotatability of the vane, the spaces are variable. The vane is mounted in the body by means of a bearing member and operates in a working medium (hydraulic oil) which is located in the space. Via one or more passages or throttle functions, the working medium can be transferred between the variable part spaces to produce the damping characteristic of the shock damper. The invention also relates to a vane damper itself and also an arrangement for a vane damper and use of one or more extruded aluminium or alloy products which can be cut in order to produce units.
Vane damper constructions are known. For example, it is previously known, in connection with steering gear, for motorcycle handlebars for example, to use vane dampers in order to counteract forceful steering movements. In connection with toilet seats, it is also previously known to use vane dampers in connection with seats which can be raised and lowered. The known vane dampers are each provided with one or more spaces, in which one or more vanes operate. The body of the vane damper also has a bearing space for the bearing part of the vane, which part may comprise a cylindrical part, by means of which the vane can be rotated in a cylindrical recess. The cylindrical part has a projecting spindle or equivalent member which is intended to engage in a part in the vehicle or equipment which is to be damped (shock-damped) in its movements.
Problems of space often arise in connection with vehicles and equipment which are to be provided with shock dampers. In cars for example, the so-called packing problem for components is significant. Conventional shock dampers are tied to a certain given shape (elongate shape) which, in various connections, it is desirable to be able to change and vary to a great extent so that the shock dampers in the vehicle do not encroach on the passenger or baggage space, for example, or force the car constructor to depart from the shape of the external design desired. The possibility of changing or varying the external shape and dimensions of the shock damper must not be exploited at the expense of the functioning of the shock damper. The present invention aims to solve this problem.
It is moreover desirable to be able to reduce the weights of shock dampers considerably. In the case of particularly low-consumption vehicles, every reduction in weight is important. In this connection, the overall effect of reduction of the weight of the vehicle is to be taken into account. It is not only the advantages which can be achieved by weight reduction in the shock damper itself but also the resultant effects from the point of view of weight reduction which apply for the vehicle as a whole thanks to the shape of the shock damper that are to be borne in mind. As far as weight reduction on the shock damper itself is concerned, there is a requirement to be able to reduce the weight of the shock damper by 20-40%. The invention solves these problems also.
There is also a requirement to be able to make more efficient and automate to a great extent the manufacture of modern shock dampers. Shock dampers for vehicles constitute a so-called mass product which must be supplied rapidly and efficiently at the same time as the shock damper function can maintain the high level of functioning and performance aimed for. The invention solves these problems also.
In connection with the new shock dampers, it is important to be able to avoid suction cup effects between the movable vane and walls opposite the latter in the body space. Furthermore, it is to be possible to avoid the release of air and of light fractions in the working medium used. The accumulator function, permits the working medium to expand and contract according to temperature changes in the shock damper and its surroundings, must be able to function in spite of demands for new geometries and reduced external dimensions. The invention solves these problems also.
It must be possible for the mounting of vane dampers in the vehicle concerned to be clear and to function well. It must be possible to carry out machining of the interacting surfaces between the pivotable vane and the relevant surfaces of the body very easily. The interacting surfaces must be easily accessible for machining tools during manufacture and it must be possible to reduce the amount of machining/treatment itself as well as the size of the surfaces which are to be machined. The invention solves these problems also.
It is also important that the shock damper function itself can be performed in a rational manner so that the desired damping characteristics and functions can be maintained. The action of the bleed function arrangement for reducing damping forces in the case of small movements must be long-term and not easily stopped up by products in the working medium. The invention solves these problems also.
It is to be possible for the new shock dampers to operate with a long service life and require little or no service. The invention solves this problem also.
A method according to the invention can be considered to be mainly characterized in that the vane with associated bearing member is produced by means of extruding aluminium or alloy, in that the extruded product is cut for production of the respective vane with associated bearing member and in that the respective vane is provided with sealing members which establish a seal against the relevant surfaces of the space and of the bearing member.
In one embodiment of the inventive idea, the tubular side wall of the body is also made by extruding aluminium or alloy. The extruded side wall product is cut to produce the respective body side wall and side parts sealing the space are fixed to the respective cut side wall. The parts can be fixed by means of adhesive bonding, rivets, bands, welding etc. In a further embodiment, only certain parts of the surfaces of the body, which interact with the movable surfaces of the vane, are sealed. In the bottom part of the body, a recess or a groove can be formed, which makes it possible for the working medium, for the purpose of performing the bleed function, to pass between the part spaces within a first operating range of the vane. Within this operating range, the vehicle or corresponding equipment concerned is provided with damping by the shock damper when the vehicle or equivalent is subject to a small load or a small force. In a second operating range of the vane, the latter operates beyond the groove to provide stronger damping, that is to say without the bleed function, effected in the second operating range. This is advantageous in the case of loads in and great forces on the vehicle. In connection with production of the extruded product, asymmetrical ducts are formed, in the body, between the part spaces and a space which serves as a gas accumulator space, into which it is possible for the working medium to expand against the action or a gas medium located in the space and to contract with the aid of the gas medium.
A vane damper according to the present invention can be considered to be mainly characterized in that the body is, in its upper end part, designed with a second space which contains gas and in that the first and second part spaces are interconnected via one or more passages via which the working medium in the first space is afforded the possibility of expanding to the second space when the working medium expands and also the working medium in the second space has the possibility of being moved back to the first space with the aid of the gas when the working medium decreases in volume.
In a preferred embodiment, the one or more passages are designed to throttle the working medium more in a first direction from the first space to the second space than in a second direction from the second space to the first space.
A vane damper according to the present invention is mainly characterized in that, in the fully rotated position of the vane in a first direction, a first side part space remains so as to prevent adhesion effects between the mutually opposite surfaces of the vane and of the body and also release of air or light fractions in the working medium. In the fully rotated position in a second direction, a second side part space is present in order to prevent adhesion effects between the opposite surfaces in this case of the vane and of the body and also to prevent the release effects in the working medium.
A vane damper according to the invention can be considered to be mainly characterized in that there are arranged in the vane one or more continuous holes and one or more shims arranged at this or these hole(s), by means of which hole(s) a damping force/damping capacity/damping characteristic brought about by the vane can be effected. In or near the vane, one or more connections can also be arranged between the part spaces, which connections perform one or more bleed functions, for example one or more grooves arranged in the delimiting surface of the body, where different grooves and groove shapes can provide bleed functions of different nature.
An arrangement according to the invention can be considered to be mainly characterized in that only a part of the space inner surfaces undergoes machining which ensures an effective sealing function by means of sealing members.
One embodiment includes, among the space inner surface parts, a first curved space inner surface which is opposite the free end edge surface of the vane. The curved space inner surface is finished so as to ensure functionally reliable sealing by means of and via a sealing member. The sealing member is arranged at the curved surface and the front end edge surface, and is preferably fixed on the free end edge of the vane. The sealing is effected when the front edge of the vane sweeps over the curved inner space surface in the performance of its damping function/damping characteristic.
A further embodiment also includes curved inner space surfaces which are opposite an outer surface on a cylindrical bearing part belonging to the vane, by means of which part the vane is mounted in a circular space in the body. Only parts, for example between 10 and 30%, of the curved inner space surfaces are machined so as to bring about reliable sealing between the outer surface and the parts of the curved inner space surfaces with sealing strips, preferably located on or in the cylindrical bearing part, in between.
In a further embodiment, the side parts of the body, which, together with the tubular side wall of the body, are only partially machined (that is to say ground, polished etc.) to bring about reliable sealing between the upper and lower edges of the vane with sealing strips, preferably fastened to the vane, in between.
An arrangement according to the present invention can be considered to be mainly characterized in that the bearing unit of the vane is provided with a hole, in which a rotating member, for example a rotary spindle, belonging to a part (chassis, wheel, vehicle etc.) extends, the movements of which part are to be damped by the vane damper.
In one embodiment, the body is anchored in a vehicle or in a unit on or in which damping is intended to be performed by means of the vane damper, and the part which is to have its movements damped belongs to or is mounted in the vehicle/unit.
A use according to the invention can be considered to be mainly characterized in that the extruded aluminium or alloy product(s) which can be cut for production of units is characterized in that the product(s) is (are) used in order to produce as units a vane with associated bearing part, forming part of a vane damper, and/or a tubular side wall forming part of the body of a vane damper.
According to the above, a rational and functionally reliable vane shock damper can be produced at relatively low cost when the price and design of the vehicle are also taken into consideration. Great packing density can be achieved in the vehicle/equipment concerned thanks to a changed external variable geometry and often reduced external dimensions. Great reductions in weight on the shock damper itself can be achieved. Furthermore, weight reductions and design advantages can be achieved on the vehicle itself.